Glaucoma is a progressive disease which leads to optic nerve damage and, ultimately, total loss of vision. The causes of this disease have been the subject of extensive studies for many years, but are still not fully understood. The principal symptom of, and/or risk factor for, the disease is elevated intraocular pressure (IOP) or ocular hypertension.
The reasons why IOP is increased in glaucoma patients are not fully understood. It is known that elevated IOP can be at least partially controlled by administering drugs which either reduce the production of aqueous humor within the eye, such as beta-blockers and carbonic anhydrase inhibitors, or increase the flow of aqueous humor out of the eye, such as cholinergic agonists and sympathomimetics.
All types of drugs currently being used to treat glaucoma have potentially serious side effects. Cholinergic agonists such as pilocarpine can cause blurring of vision and other ocular side effects, which may lead either to decreased patient compliance or to termination of therapy. Systemically administered carbonic anhydrase inhibitors can also cause serious side effects, such as nausea, dyspepsia, fatigue, and metabolic acidosis which can affect patient compliance and/or necessitate the withdrawal of treatment. Moreover, some beta-blockers have been known to be associated with pulmonary side effects attributable to their effects on beta-2 receptors in the pulmonary tissue. Sympathomimetics cause tachycardia, arrhythmia and hypertension. There is therefore a continuing need for new therapies which control elevated IOP associated with glaucoma.
Activator protein-1 (AP-1) is a dimeric gene transcription promoter comprised of subunit proteins which are the products of at least three different proto-oncogene families: the Jun (c-Jun, v-Jun, JunB, JunD), Fos (c-Fos, v-Fos, FosB, FosB2, Fra-1, Fra-2) or activating transcription factor (B-ATF, ATF2, ATF3/LRF1) families. Uncomplexed monomers and homo- and hetero-dimers of these protein subunits have been observed in a variety of mammalian and non-mammalian tissues (Foletta et al., Transcriptional regulation in the immune systems: all roads lead to AP-1, J. Leukoc Biol. volume 63, pages 139–152 (1998); and Karin et al., AP-1 function and regulation, Curr. Opin. Cell Biol., volume 9, pages 240–246 (1997)).
AP-1 binds to specific DNA sequences within enhancer regions of many genes (e.g., TPA (12-O-tetradecanoylphorbol-13-acetate) response elements (TREs) or cyclic AMP response elements (CREs)) and promotes the activation of the particular gene. Examples of genes which contain AP-1 consensus seqences in their enhancer regions include the genes for SV40 and human metallothionein IIA (Lee et al., Activation of transcription by two factors that bind promoter and enhancer sequences of the human metallothionein gene and SV40, Nature, volume 325, pages 368–372). The binding affinity of AP-1 for the various response elements appears to depend on the specific protein subunit dimer complex. Dimers composed of Jun/Jun or Jun/Fos generally bind TREs, whereas ATF/ATF or Jun/ATF dimers preferentially bind CREs (Whitmarsh et al., Transcription factor AP-1 regulation by mitogen-activated protein kinase signal transduction pathways, J. Mol. Med., volume 74, pages 589–607 (1996); and Karin et al., Current Opin. Cell Biol., volume 9, pages 240–246 (1997)). The biological consequences of AP-1 mediated gene transcription may also vary, depending upon the dimer composition. For example, induction of murine glutathione-S-transferase genes is apparently mediated by a Fos/Jun heterodimer which binds at least one TRE sequence within the gene's antioxidant response element (Ainbinder et al., Regulatory mechanisms involved in activator-protein-1 (AP-1)-mediated activation of glutathione-S-transferase gene expression by chemical agents, Eur. J. Biochem., volume 243, pages 49–57 (1997); Xie et al., ARE-and TRE-mediated regulation of gene expression, J. Biol. Chem., volume 270, pages 6894–6900 (1995)), and a c-Jun/ATF-2 complex has been shown to bind to a CRE involved in activation of the T-cell gene for tumor necrosis factor-alpha (Foletta et al., J. Leukoc. Biol., volume 63, pages 139–152 (1998)).
Several AP-1 Activators have been reported previously, including β-naphthoflavone and tert-butylhydroquinone (tBHQ) (Ainbinder et al., Eur. J. Biochem., volume 243, pages 49–57 (1997); Ainbinder et al., Signaling pathways in the induction of c-fos and c-jun proto-oncogenes by 3-methylcholanthrene, Receptors and Signal Transduction, volume 7, pages 279–289 (1998); and Oazki et al., The comparative effects of haloperidol, (−)-sulpiride, and SCH23390 on c-fos and c-jun mRNA expressions, and AP-1 DNA binding activity, Eur. Neuropsychopharmacol., volume 7, pages 181–187 (1997)). Nowhere in the art, however, has it been taught or suggested that AP-1 activators may be useful in treating glaucoma or ocular hypertension.